High voltage transformer

ABSTRACT

A high voltage transformer whose primary and secondary windings are separated by a lamination of solid insulation and conductive sheets alternately arranged. The conductive sheets are charged with discrete direct current voltages to provide a predetermined voltage gradient across the composite insulator structure. In a preferred embodiment the insulating components and the conductive components are in the form of concentric cylinders.

United States Patent 91 Ashe [54] HIGH VOLTAGE TRANSFORMER [76]Inventor:

Monica, Calif. 90403 [22] Filed: June 15, 1971 [21] Appl. No.: 153,310

[52] US. Cl. ..336/70, 336/84, 336/223 [51] Int. Cl. ..H0lf 15/00 [58]Field of Search ..336/84, 69, 70, 223

[56] References Cited UNITED STATES PATENTS Harry Ashe, 1040 Euclid St.,Santa 1 3,736,542 51 May 29,1973

2,388,848 11/1945 Howe ..336/84 X FOREIGN PATENTS OR APPLICATIONS1,271,669 8/1961 France ..336/84 Primary Examiner-Thomas J. KozmaAttorney-Harry A. Herbert, Jr. and Willard R.

Matthews J r.

[57] ABSTRACT A high voltage transformer whose primary and secondarywindings are separated by a lamination of solid insulation andconductive sheets alternately arranged. The conductive sheets arecharged with discrete direct current voltages to provide a predeterminedvoltage gradient across the composite insulator structure. In apreferred embodiment the insulating components and the conductivecomponents are in the form of concentric cylinders.

1 Claim, 2 Drawing Figures PATENTEDMY'ZQ 197s :F'IE .1

- mvsw'ron HARRY- vASH a/ Km ATTORNEYS BACKGROUND OF THE INVENTION Thisinvention relates to high voltage transformers and in particular to newand improved means for insulating the transformers primary and secondarywindings.

The manufacture of high voltage transformers has in the past requiredcostly equipment and has, in general, produced large cumbersome devices.In order to support the high potentials between primaries andsecondaries, it has been customary to resort to oil impregnation and oilfilled casings. Impregnated paper insulation often has to be toroidallywound around the transformer windings. The-oil filled units are bothcostly and cumbersome. The alternative brute force" method of simplyusing thicker insulation becomes impractical when very high voltages areencountered. In order to reduce the size of high voltage transformerspotting in an insulation type thermoset plastic has been used. Thisapproach however, requires expensive pressurevacuum systems and longfabrication times (due to the cooling cycle of the plastic insulationmaterial). There currently exists therefore, the need for a transformermanufacturing technique that eliminates much of the bulk andinconvenience of oil impregnated and oil filled transformer and thatdoes not require costly and time consuming fabrication equipment andprocedures.

' The present invention is directed toward accomplishing these and otherends.

SUMMARY OF THE INVENTION drical segments of solid insulation areconcentrically arranged with layers of conductive material betweenadjacent insulators. A uniform potential gradient is maintained acrossthe composite insulation structure by means of direct current voltagesapplied to the conductive layers. There is thus provided an insulatingstructure that can be easily fabricated and assembled and that supportsmaximum voltage for any given insulation thickness.

It is a principal object of the invention to provide a new and improvedhigh voltage transformer.

It is another object of the invention to provide, in a high voltagetransformer, voltage insulating means that can be easily fabricated andassembled.

It is another object of the invention to provide insu lating means foruse in a high voltage transformer that supports maximum potential forany given insulation thickness.

It is another object of the invention to provide a high voltagetransformer having solid insulating means between its primary andsecondary windings.

These together with other objects, features, and advantages of theinvention will become more readily apparent from the following detaileddescription when taken in conjunction with the accompanying drawings.

DESCRIPTION OF DRAWINGS FIG. 1 is a sectional view of a high voltagetransformer embodying the principles of the present invention; and,

FIG. 2 is a sectional view of the high voltage transformer of FIG. 1taken at 22.

DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2,there is illustrated thereby one presently preferred embodiment of theinvention. Primary winding 5 which may be an appropriate insulated wireas dictated by the specifications of the transformer is wound aroundcore member 3 and insulated therefrom by insulation layer 4. Inpractice, of course, core 3 and insulation 4 can be replaced by a simplecoil form. The insulation structure between primary winding 5 andsecondary winding 13 comprises a multiplicity of concentric cylindricalmembers that are alternately of insulating and conducting material.Cylindrical members 6, 8, l0 and 12 are fabricated of solid insulatingmaterial. Cylindrical members 7, 9, and 11 are thin metal members. Allcylindrical members fit in close contiguity. Secondary winding 13comprises many turns of appropriate insulated wire wound overcylindrical insulating member 12. The outer surface of secondary winding13 is also covered with appropriate insulation. Primary leads 16 andsecondary leads 15 are brought out of the transformer in theconventional manner. Since it is not pertinent to the inventioninsulation at the ends of the transformer is not shown. It would inpractice normally be used however. A direct current supply 20 provides acertain bias to each of the conductivecylindrical members. These biasesare selected to provide the desired voltage gradient across thecomposite insulation structure. Insulation materials and thickness,primary and secondary wire size and turns, and the various directcurrent bias values are of course design details to be dictated by thespecifications of the particular transformer being fabricated.

While the invention has been described in its preferred embodiment, itis understood that the words which have been used are words ofdescription rather than of limitation and that changes within thepurview of the appended claims may be made without departing from thetrue scope and spirit of the invention in its broader aspects.

What is claimed is:

1. A high voltage transformer comprising acore member of permeablematerial, a layer of insulation thereon, a primary winding wound oversaid layer of insulation, an insulating structure disposed over saidprimary winding, said insulating structure comprising outer surface ofsaid secondary winding.

1. A high voltage transformer comprising a core member of permeablematerial, a layer of insulation thereon, a primary winding wound oversaid layer of insulation, an insulating structure disposed over saidprimary winding, said insulating structure comprising not less than fiveconcentric members of insulation and conductive materials alternatelyarranged such that the inner and outer cylindrical members are ofinsulation material, means for applying a discrete direct currentvoltage to each said conductive cylindrical member, said discretevoltages having relative values that provide a uniform potentialgradient across said insulating structure, a secondary winding woundover said insulating structure, and insulating means disposed on theouter surface of said secondary winding.